Barack Obama sealed the Democratic presidential nomination yesterday, a historic step towards his once-improbable goal of becoming the first black United States president. Meanwhile, a defeated Hillary Rodham Clinton manoeuvred for the vice-presidential spot on his ticket.

Obama's victory sets up a five-month campaign against Republican John McCain, a race between a 46-year-old opponent of the Iraq War and a 71-year-old former Vietnam prisoner of war and staunch supporter of the current US military mission.

They will vie to succeed President George W. Bush, whose popularity ratings continue to plunge.

Obama, a first-term Illinois senator, beat Clinton, the former first lady, in a 17-month marathon for the Democratic nomination.

Unexpected

But Clinton's declaration of an interest in becoming his running mate was unexpected.

"I am open to it" if it would help the party's prospects in November, Clinton said yesterday of the union which could shore up support among Hispanics for Obama.

Up to press time, Obama's campaign had made no response to Clinton's comments.